Medical Microbiology Commons^™

Mechanisms Of Behavioral Change In Hosts Of Toxoplasma Gondii: A Review, Olivia Grimsley

Senior Honors Theses

The parasite Toxoplasma gondii is a highly ubiquitous parasite that latently infects an estimated 33% percent of the global population. Toxoplasmosis is of obvious clinical significance due to the extremely high risks to the unborn who contract it congenitally. Less attention has been given to a more subtle aspect of latent infection, which is the behavioral alterations that are commonly experienced by those who contract the parasite. Infected individuals commonly display a variety of altered behaviors, such as increased aggression and risk-seeking behaviors, depression, higher tendency towards suicide and self-directed violence, a loss of fear response, and a greatly increased …

The Attitudes And Perspectives Of Laboratory Professionals On The Use Of Machine Learning Combined With Maldi For Viral Identification: A Qualitative Study, Grace Johnson

Honors Projects

The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with machine learning (ML) has been proposed by numerous studies as a novel approach for viral identification. However, the development and implementation of this instrumentation is still in its early stages, and laboratory professionals' perspectives on its feasibility, accuracy, implementation, and effect on current laboratory operating procedures remain underexplored.

This study aimed to investigate laboratory professionals’ attitudes and opinions regarding the use of MALDI-TOF-MS coupled with machine learning for viral identification, focusing on perceived benefits, barriers, and factors that would affect participants’ opinions on implementation.

A qualitative descriptive research …

Enriched Pathways In Gut Microbiome Predict Response To Immune Checkpoint Inhibitor Treatment Across Demographic Regions And Various Cancer Types, Xunhui Cai, Jennifer Y Cho, Lijun Chen, Yufeng Liu, Fenghu Ji, Katia Salgado, Siyi Ge, Dehua Yang, Hui Yu, Jianbo Shao, P Andrew Futreal, Boris Sepesi, Don Gibbons, Yaobing Chen, Guoping Wang, Chao Cheng, Meng Wu, Jianjun Zhang, Ansel Hsiao, Tian Xia

Faculty, Staff and Student Publications

Understanding the effect of gut microbiota function on immune checkpoint inhibitor (ICI) responses is urgently needed. Here, we integrated 821 fecal metagenomes from 12 datasets to identify differentially abundant genes and construct random forest models to predict ICI response. Gene markers demonstrated excellent predictive performance, with an average area under the curve (AUC) of 0.810. Pathway analyses revealed that quorum sensing (QS), ABC transporters, flagellar assembly, and amino acid biosynthesis pathways were enriched between responders (R) and non-responders (NRs) across 12 datasets. Furthermore,

87 - Maternal Dental Status And Caries Among Siblings, Monica Walker, Charity Hammond, Angela Wilson, Denise Mckinney, Katie Protogyrou

Undergraduate Research Symposium

Research has suggested that birth order or environmental factors affect siblings' oral health status during childhood. However, more recent research suggests that the strongest predictor of children's oral health status is the mother's oral health status. This project investigated the association between the oral health status of the mother during pregnancy and bacteria (biofilms) identified in cavitated lesions (dental caries) of their children’s exfoliated primary teeth. Five consenting maternal participants anonymously donated their children's primary teeth and completed a questionnaire about their oral health status during each pregnancy. After visually identifying the exfoliated teeth with dental caries, the biofilms were …

The Microbiome-Restorative Potential Of Ibezapolstat For The Treatment Of Clostridioides Difficile Infection Is Predicted Through Variant Polc-Type Dna Polymerase Iii In Lachnospiraceae And Oscillospiraceae, Jacob K Mcpherson, Julian G Hurdle, Matthew L Baker, Tahir Hussain, Ashok Kumar, Kevin W Garey

Faculty, Staff and Student Publications

Ibezapolstat (IBZ), a first-in-class antibiotic targeting the PolC-type DNA polymerase III alpha-subunit (PolC) in low G + C bacteria, is in clinical development for the treatment of Clostridioides difficile infection (CDI). In the phase 2 trials, IBZ had potent activity against C. difficile while sparing or causing regrowth of Lachnospiraceae, Oscillospiraceae, and Erysipelotrichales, common commensal low G + C bacteria. The purpose of this study was to utilize in silico approaches to better interpret the narrower than expected IBZ spectrum of activity. IBZ susceptibility to human commensal microbiota was predicted using genomic analysis and PolC phylogenetic tree construction in relation …

The Medicine From Nature; Finding The Antibacterial Power Of Essential Oils, Josi Maness, Seoyeon Kim, Eric T. Gillock

SACAD: Scholarly Activities

Essential oils are known to have pharmaceutical effects such as anti-inflammatory, antioxidant, and anticarcinogenic properties. These days, there are various types of essential oils that are commonly used for coughing or to promote good sleep.

We prepared 19 different essential oils to find the essential oil that has the most antibiotic properties by putting drops of oil on a soy agar plate with Serratia marcescens. As a result, cinnamon cassia essential oil was most effective, and five of them didn't have antibiotic properties.

We also tested with six different types of antibiotics, and as a result, only three of them …

Dengue Cases In Hanoi, Vietnam: Unseasonal Surge Foreshadows Increased Incidence That Demands Organized Preventive Action, Andrew W. Taylor-Robinson

Chulalongkorn Medical Journal

Letter to the Editor - Abstract not required.

Exploring The Mechanisms Of Varicella-Zoster Virus Pathogenesis And Its Potential Role In Oncogenesis, Fernando Cisneros, Blake Martin

Research Symposium

Background: Varicella-zoster virus (VZV) is a highly prevalent pathogen primarily recognized for causing chickenpox during primary infection and herpes zoster (HZ), also known as shingles, upon reactivation. While post-infectious complications of VZV, such as encephalitis, pneumonia, and post-herpetic neuralgia, are well-established, recent large population-based studies suggest that HZ may increase the risk of occult cancers. Emerging evidence suggests that VZV may modulate key oncogenic pathways, such as the inhibition of apoptosis, alteration of cell cycle regulatory enzymes, and interference with immunosurveillance, which could potentially promote cancer development. These findings indicate that VZV’s role in cancer biology may involve direct cellular …

Exploring Oxylipins In Host–Microbe Interactions And Their Impact On Infection And Immunity, Robert J. Neff, Christopher D. Radka

Markey Cancer Center Faculty Publications

Plasma lipids are essential components of biological systems, transported through interactions with proteins to maintain cellular functions. These lipids exist in various forms, such as fatty acids, glycerolipids, glycerophospholipids, sphingolipids, sterols, and prenol lipids, derived from dietary intake, adipose tissue, and biosynthesis. While the association between certain fatty acids and cardiovascular diseases has been widely recognized, polyunsaturated fatty acids (PUFAs) exhibit cardioprotective effects, reducing risks of arrhythmias and heart-related mortality. This is due to their role in the production of eicosanoids, which modulate inflammation. Chronic inflammation, particularly in obesity, is significantly influenced by fatty acids, with saturated fatty acids promoting …

Extracellular Vesicles Released By All Patients Contain Hne-Adducted Proteins: Implications Of Collateral Damage., Jenni Ho, Suriyan Sukati, Tamara Taylor, Sherry Carter, Brittany Fuller, Amy Marmo, Caryn Sorge, John D'Orazio, D Allan Butterfield, Subbarao Bondada, Heidi Weiss, Daret K St Clair, Luksana Chaiswing

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Off-target neuronal injury is a serious side-effect observed in cancer survivors. It has previously been shown that pediatric acute lymphoblastic leukemia (ALL) survivors have a decline in neurocognition compared to healthy age-matched counterparts. Elevated oxidative stress has been documented to be a mediator in off-target tissue damage in cancer survivors. Early detection of oxidative stress markers may provide an opportunity to prevent off-target tissue damage. Extracellular vesicles (EVs) have surfaced as a potential diagnostic tool due to molecular cargo they contain. We investigated the potential for EVs to be a sensitive indicator of oxidative stress and off-target tissue damage by …

Nkapl Facilitates Transcription Pause-Release And Bridges Elongation To Initiation During Meiosis Exit, Zhenlong Kang, Chen Xu, Shuai Lu, Jie Gong, Ruoyu Yan, Gan Luo, Yuanyuan Wang, Qing He, Yifei Wu, Yitong Yan, Baomei Qian, Shenglin Han, Zhiwen Bu, Jinwen Zhang, Xian Xia, Liang Chen, Zhibin Hu, Mingyan Lin, Zheng Sun, Yayun Gu, Lan Ye

Faculty, Staff and Students Publications

Transcription elongation, especially RNA polymerase II (Pol II) pause-release, is less studied than transcription initiation in regulating gene expression during meiosis. It is also unclear how transcription elongation interplays with transcription initiation. Here, we show that depletion of NKAPL, a testis-specific protein distantly related to RNA splicing factors, causes male infertility in mice by blocking the meiotic exit and downregulating haploid genes. NKAPL binds to promoter-associated nascent transcripts and co-localizes with DNA-RNA hybrid R-loop structures at GAA-rich loci to enhance R-loop formation and facilitate Pol II pause-release. NKAPL depletion prolongs Pol II pauses and stalls the SOX30/HDAC3 transcription initiation complex …

Pathogenesis, Diagnosis, And Examination Of Corynebacterium Diphtheriae, Ika Ningsih, Muhammad Iqbal Safrullah

Indonesian Journal of Medical Chemistry and Bioinformatics

Corynebacterium diphtheriae is a rod-shaped bacterium, Gram-positive (purple), growth requires the presence of oxygen or can live with oxygen or without oxygen, nonmotile, non-capsular, non-sporing, catalase positive. Most species ferment carbohydrates such as fructose, galactose, glucose, maltose, and mannose and produce an exotoxin called diphtheria toxin (DT) which can cause diphtheria, a respiratory infection characterized by sore throat and the production of a thick layer / gray pseudomembrane and generally affects children aged 15 years and under and is very vulnerable in people who are not immunized and in low immune systems. Diphtheria is a dangerous and life-threatening disease if …

Characterization Of Vaccine-Enhanced Humoral Immune Responses Against Emergent Sars-Cov-2 Variants In A Convalescent Cohort, Jared Sheehan, Amber J. Trauth, Michael E. Hagensee, Alistair J. Ramsay

School of Graduate Studies Faculty Publications

Vaccination of COVID-19–convalescent individuals may generate ‘hybrid’ immunity of enhanced magnitude, durability, and cross-reactive breadth. Our primary goal was to characterize hybrid antibody (Ab) responses in a patient cohort infected with ancestral Wuhan-Hu-1 virus and vaccinated between 6 and 10 months later with the Wuhan-Hu-1–based BNT162b2 mRNA vaccine. We were particularly interested in determining the efficacy of neutralizing Ab responses against subsequently emergent SARS-CoV-2 variants. Sera collected at 3-monthly intervals over a period of 12 months were analyzed by ELISA for SARS-CoV-2 RBD–specific Ab responses, and also for neutralizing Ab activity using pseudovirus-based neutralization assays. We found that convalescent RBD-reactive …

In Vivo Evaluation Of Novel Nanoparticles And Repurposed Pharmaceuticals To Combat Antimicrobial Resistance, Sarah E. Evans

Theses, Dissertations and Capstones

In a 2019 report by the Centers for Disease Control and Prevention (CDC), infections resistant to antibiotic treatment amount to about three million infections and 48,000 deaths. Antimicrobial resistance is an escalating global threat as existing antibiotics lose efficacy over time. The project described is focused on partnering with pharmaceutical researchers and producers to test new nanoparticle-based or repurposed compounds. The central hypothesis of this thesis is that pharmaceutical formulations such as nanoparticles may provide a cost-effective means of combating the emerging antimicrobial resistance. The nanoparticle compounds allowed for a wide range of customization for the pharmaceutical design, since the …

A Thermodynamic Bottleneck In The Tca Cycle Contributes To Acetate Overflow In Staphylococcus Aureus, Nabia Shahreen, Jong-Sam Ahn, Adil Alsiyabi, Niaz Bahar Chowdhury, Dhananjay Shinde, Sujata S. Chaudhari, Kenneth W. Bayles, Vinai Chittezham Thomas, Rajib Saha

Journal Articles: Pathology and Microbiology

During aerobic growth, S. aureus relies on acetate overflow metabolism, a process where glucose is incompletely oxidized to acetate, for its bioenergetic needs. Acetate is not immediately captured as a carbon source and is excreted as waste by cells. The underlying factors governing acetate overflow in S. aureus have not been identified. Here, we show that acetate overflow is favored due to a thermodynamic bottleneck in the TCA cycle specifically involving the oxidation of succinate to fumarate by succinate dehydrogenase. This bottleneck reduces flux through the TCA cycle, making it more efficient for S. aureus to generate ATP via acetate …

Quaternized Chitosan Derivatives Inhibit Growth And Affect Biofilm Formation Of Staphylococcus Aureus, Alex Miranda, Nichole D. Brandquist, Kristen Johnson, Elena Muldiiarova, Aleksandr Fadeev, Mahboubeh Ghanbari, Jennifer L. Endres, Kenneth W. Bayles, Jason N. Mactaggart, Denis Svechkarev, Marat Sadykov, Yury Salkovskiy

Journal Articles: Pathology and Microbiology

Antimicrobial resistance (AMR) poses a global health threat, severely impeding the effective treatment of bacterial infections and jeopardizing the safety of routine medical procedures. Methicillin-resistant Staphylococcus aureus (MRSA) is particularly problematic because of its resistance to beta-lactams and the ability to form resilient biofilms. Conventional antibiotics, including last-resort options, have serious side effects and may contribute to further resistance. Chitosan, a natural biopolymer, offers a promising alternative due to its biocompatibility and antimicrobial properties, though its effectiveness against biofilms is limited. Recent studies suggest that increasing the positive charge density and adding hydrophobic moieties to chitosan, can enhance its antimicrobial …

Interferon-Gamma Receptor Signaling Regulates Innate Immunity During Staphylococcus Aureus Craniotomy Infection, Zachary Van Roy, Gunjan Kak, Rachel W. Fallet, Tammy Kielian

Journal Articles: Pathology and Microbiology

A craniotomy is a neurosurgical procedure performed to access the intracranial space. In 3-5% of cases, infections can develop, most caused by Staphylococcus aureus biofilm formation on the skull surface. Medical management of this infection is difficult, as biofilm properties confer immune and antimicrobial recalcitrance to the infection and necessitate additional surgical procedures. Furthermore, treatment failure rates can be appreciably high. These factors, compounded with rapidly expanding rates of antimicrobial resistance, highlight the need to develop alternative treatment strategies to target and reverse the immune dysfunction that occurs during biofilm infection. Our recent work has identified CD4+ Th1 and Th17 …

Cd4+ T Cell-Innate Immune Crosstalk Is Critical During Staphylococcus Aureus Craniotomy Infection, Gunjan Kak, Zachary A. Van Roy, Rachel W. Fallet, Lee E. Korshoj, Tammy Kielian

Journal Articles: Pathology and Microbiology

Access to the brain for treating neurological sequalae requires a craniotomy, which can be complicated by infection. Staphylococcus aureus accounts for half of craniotomy infections, increasing morbidity in a medically fragile patient population. T cells preferentially traffic to the brain during craniotomy infection; however, their functional importance is unknown. Using a mouse model of S. aureus craniotomy infection, CD4+ T cells were critical for bacterial containment, as treatment of WT animals with anti-CD4 exacerbated infection that was similar to phenotypes in Rag1-/- mice. Single-cell RNA-Seq (scRNA-Seq) revealed transcriptional heterogeneity in brain CD3+ infiltrates, with CD4+ cells most prominent that displayed …

Pgc-1Α Activation To Enhance Macrophage Immune Function In Mycobacterial Infections, Joel R. Frandsen, Zhihong Yuan, Brahmchetna Bedi, Zohra Prasla, Seoung-Ryoung Choi, Prabagaran Narayanasamy, Ruxana Sadikot

Journal Articles: Pathology and Microbiology

Nontuberculous Mycobacteria (NTM) are a heterogeneous group of environmental microorganisms with distinct human pathogenesis. Their incidence and prevalence are rising worldwide, due in part to elevated antimicrobial resistance which complicates treatment and potential successful outcomes. Although information exists on the clinical significance of NTMs, little is known about host immune response to infection. NTM infections alter macrophage mitochondrial capacity and decrease ATP production, efficient immune response, and bacterial clearance. Transcription factor peroxisome proliferator activated receptor (PPAR) γ coactivator-1α (PGC-1α) is a master regulator of mitochondrial biogenesis, influencing metabolism, mitochondrial pathways, and antioxidant response. Mitochondrial transcription factor A (TFAM) is a …

Extracellular Adherence Proteins Reduce Matrix Porosity And Enhance Staphylococcus Aureus Biofilm Survival During Prosthetic Joint Infection, Mohini Bhattacharya, Tyler D. Scherr, Jessica Lister, Tammy Kielian, Alexander R. Horswill

Journal Articles: Pathology and Microbiology

Biofilms are a cause of chronic, non-healing infections. Staphylococcus aureus is a proficient biofilm-forming pathogen commonly isolated from prosthetic joint infections that develop following primary arthroplasty. Extracellular adherence protein (Eap), previously characterized in planktonic or non-biofilm populations as being an adhesin and immune evasion factor, was recently identified in the exoproteome of S. aureus biofilms. This work demonstrates that Eap and its two functionally orphaned homologs EapH1 and EapH2 contribute to biofilm structure and prevent macrophage invasion and phagocytosis in these communities. Biofilms unable to express Eap proteins demonstrated increased porosity and reduced biomass. We describe the role of Eap …